Confidence
by fandomtrashpanda
Summary: All King wants is to not turn into an emotional puddle every time Diane wants to get physical. Kiane (M for sexual content)
1. Chapter 1

Because I'm a slut for Kiane and have the mind of a dirty pervert.

Wag your fingers at me all you want _nothing will stop me_.

* * *

 **Confidence**

"Stupid -" _thunk_ "-stupid -" _thunk_ "-stupid -"

"I really doubt beating your head against a tree is going to make a difference, Harlequin," Helbram drawled, floating over King's head. "Besides, what's another gaffe on your list?"

"Don't remind me that there's a list," King groaned, turning around and sliding down the tree, his forehead scratched and bruised. He flipped the helmet over his face to drop his head against the tree, staring up at Helbram. "I'm hopeless."

"It's a good thing she loves that about you," his best friend snickered.

"You were eavesdropping!? But I took my coat off, the helmet was -!"

"Ha! Called it!" Helbram cheered.

"You were _bluffing_!?"

"Eavesdropping, bluffing - either way, she still loves that you get all flustered around her. So what's the big deal?"

"I don't want to be flustered!" He wailed, flopping to his side. "I want to be suave, and cool -" He was interrupted by Helbram's laughing uproariously. "You can stop that, now."

"Harlequin, you've been a lot of things, but 'suave and cool' are two words that have never been on that list," he told the disconsolate Sin.

"There was one time!" He yelled, sitting up to wave his fist at the ghost. "When I was fighting Ban before the Necropolis," he muttered, slumping onto his side again. "I was so confident that he'd fallen into my trap - ugh, but then Diane showed up and it took all of my willpower to not dissolve into a puddle right there!"

"You really are a mess," Helbram scoffed.

"Just once!" King exclaimed, holding his hand up in the air, pointing at the sky with a single finger. "Just once, I'd like to at least be able to kiss her without turning into a bumbling, sweaty mess!"

"Emphasis on the sweaty."

"You shut up!"

"Maybe you could go to Merlin for a potion or something," Helbram snorted derisively. "I mean, she's practically made a lifetime supply of those pills for Diane that make her your size, maybe she can make something that'll keep you from turning into a bumbling mess around her! Ha!" It wasn't until the words had left his mouth that Helbram realized he had made a mistake, turning to look at King to see him sitting up straight. "Harlequin, I was joking -!"

"Nope!" He sang, flipping the helmet off of his head and floating into the air while gleefully rubbing his hands together. "It's about time Diane and I visited the captain!"

XOXOXOXOXOXOXOXOXOXO

"I'm so glad the two of you decided to visit! It's so unexpected, but nice!" Elizabeth said to Diane and King.

"Well, the forest was getting boring," King said, "I figured that the city might be livelier."

"It certainly has been," Elizabeth said, "in fact, some travelling performers came through not too long ago - and Gilthunder asked them to stay!"

"Oh, really?" Diane perked up.

"Yeah, Little Gil asked them to stay because one of them beat Ban in an arm-wrestling match!" Meliodas said, Ban promptly dousing him in ale when he spat his out.

"Wait, seriously?" King laughed.

"Yeah, whatever!" He snapped, "I underestimated her. If she took me up on my challenge for a rematch I doubt it would happen again!"

"You would like her, Diane," Elizabeth said, "Sen acts really serious when you first meet her, but once you get to know her and she relaxes around you she's actually really funny!"

"Wait -" King held up his hand, his lips twitching as he tried not to smile, "you were beaten in an arm-wrestling contest by a _human woman_?" He immediately regretted the words when Diane and Elizabeth both loomed intimidatingly over him from behind.

"What'll make you happy, King, is that her sister charmed the pants off of Howzer!" Meliodas cheered, oblivious to King's distress. Fortunately, the statement broke the concentration of the two women.

"Aw, Howzer's found someone?" Diane said, smiling as she clasped her hands together. "That's so sweet!"

"What's sweet is the woman's pies~" Ban drawled.

"Here, you guys should try them!" Meliodas said, reaching into a crate behind the counter and pulling out a pie. "This one is… blueberry." At the mention of blueberries, King agreed to try it, Diane agreeing because of the idea of sweets.

"This pie is magic," King said as soon as the fork left his lips.

"I know, right?" Meliodas laughed.

"I have got to meet this girl!" Diane exclaimed, turning to Elizabeth. "Elizabeth, you have to introduce me!"

"You girls go ahead and do that, I'd like to stick around and catch up with the captain," King said, sighing happily when Diane gave him a swift kiss on the lips before leaving.

"See you in a bit, King! Love you!"

"Love you too," he sighed, floating so high his head hit the ceiling.

"God, the two of you are disgusting~" Ban snorted.

"Like you were any better with Elaine," was King's retort.

"Point taken~"

"So, King, what did you want to catch up with me about?" Meliodas asked, crossing his arms.

"Travelling performers, invited to live in the city by Gilthunder himself? What's so special about them? Besides the magic pies."

"You'd have to see it to believe it, King," the captain told him after tapping his chin.

"Fine, be that way," King huffed, "I guess I'll go with Diane and Elizabeth after all."

"Okay, see you later!" He beamed as King floated out of the door.

"That was insultingly easy," Helbram said.

"I know, right?" He hummed. "Now, off to Merlin's lab…"

XOXOXOXOXOXOXOXOXOXO

"So, let me get this straight…" Merlin said slowly, eyeing King as he stood across the table from her, his entire face beet red. "You want me to make you a potion… that will give you confidence?" King nodded stiffly. "What's this about, King?" She asked, folding her arms while smiling at him. "Something tells me it has to do with Diane."

"It does," he choked, wincing when his voice cracked. "I - we've known each other for years, you think I would be completely relaxed around her, and a lot of the time I am! But when it matters I get all flustered and nervous and then she giggles and tells me how cute I am and that's great but I don't want to be cute!" He finished in a rush, gasping for air. He looked at Merlin with desperation in his eyes, dread creeping up within him when he saw the look of amusement glittering in hers.

"You don't want to be cute… you want to be sexy," she summarized. King felt like he was on fire, but he nodded. "It won't be easy," she told him. "Changing physical traits, such as Diane's size, is easy for me. But personality traits… not so much."

"You're Merlin," King said, eyeing her with heavy suspicion, "everything is easy for you."

"Oh, King, you flatter me," she said, "but it will take some time for me to make something that'll give you the boost of confidence you need. Tell me, have you ever experienced the kind of confidence you're looking for?"

"Once," he admitted, clenching his hands into fists. "Last year, at the Necropolis - when I still thought Ban had killed my sister, I set a trap and when he walked into it, I -" he groaned and his shoulders slumped. "I felt so cool," he muttered, "but now I feel guilty just thinking about it." He looked up when he heard Merlin chuckling.

"King…" she said slowly, "I know exactly what you need."

"Huh? You do?" He exclaimed.

"Yes. And it won't be that difficult to make. But all the same, I'm a very busy woman." King groaned and rolled his eyes.

"What do you want in exchange?" He sighed. To his surprise she picked up a syringe and a small vial.

"A sample of your blood," she said.

"What?" He whispered in disbelief.

"Oh, come on, King. I'm not asking for one of your fingers, or for your body if you die," she laughed. "All I want is a sample of your blood."

"Why do you need a sample of my blood?" He asked.

"For the same reason I have blood samples from the rest of the sins - with the exception of Gowther," she said. "My help comes at a price, King. So, what will it be?" King looked between the syringe and Merlin's eyes before rolling his own with a sigh.

"Which arm?"

XOXOXOXOXOXOXOXOXOXO

 _"Come back in a few hours."_ She had told him while returning to her workbench.

King floated through the city, bored. He just had to kill time for a few hours until Merlin was done.

"Hey! King!" He perked up and smiled, flying down to Diane's side when he spotted her and Elizabeth, talking to a girl with curly green hair. There was the vague smell of fresh pastries in the air, but all other observations became irrelevant when Diane slipped her hand into his and kissed his cheek as soon as he was next to her. "King, this is Celia! The girl who made those pies the captain has," Diane introduced him to the girl with the green curls.

"Nice to meet you," she said, shaking his hand.

"Oh, right - you're the one who's charmed the pants off of Howzer, right?" Her eyes widened with surprise before she burst into a fit of laughter, slapping her knee because she was laughing so hard.

"I've been trying!" She declared happily.

"Yeah, me too," Diane muttered, barely loud enough for King to hear. Or he might have been hearing things; either way, he felt the flush in his cheeks spread all the way back to his ears and down is chest.

XOXOXOXOXOXOXOXOXOXO

"Just once?" King said, looking at the small vial of blue liquid that Merlin had given him.

"Yes. It's simple enough. Once you've had it once, all you need to do is recall the moment you're trying to emulate, and it should come easier."

"That's all?" He exclaimed.

"I can't change who you are, King," Merlin told him firmly, "I can only give you a push in the right direction." He stared at her intently for a few moments before taking a deep breath and knocking back what was in the vial in a single gulp.

"It takes like blueberries," he said, blinking in surprise when Merlin slipped the vial from his hand.

"It's impressive, isn't it?" She said, looking at it with a smirk on her face.

"Uh, yeah… sure…" he said, floating backwards. "Thanks, Merlin."

"Don't mention it, King," she told him while turning around to return to her workbench. It wasn't until he was long gone that she picked up the vial of his blood and looked at it closely. "I almost feel guilty for this one," she murmured to herself, using a spell to open a secret compartment in the wall of her lab, revealing a steel test tube rack. She slipped the vial of King's blood into the last empty space.

"I wonder how he would feel if he found out I gave him crushed blueberries…"

XOXOXOXOXOXOXOXOXOXO

"Captain!" The bar was closed for the night, and Meliodas was surprised to see King flying in just as he was about to lock the door.

"Hey, King, what's up?" He asked.

"I need your help," he said in a rush, looking around outside before ducking into the tavern and closing the door. "Are you alone?"

"Well, Elizabeth invited Diane to spend the night in the castle, Ban is passed out drunk upstairs - which means the usual crowd is out. So, yeah, I'm alone." He watched as King took a few deep breaths before opening his eyes with a determined expression.

"Captain -" he said, clapping his hands down on Meliodas' shoulders and staring into his eyes with beet red cheeks, "-I need you to tell me everything you know about p-pleasuring women." The request spilled out of him in a single breath and he gasped with relief, slumping over on Chastiefol.

"You got that out in one sentence and only stuttered once? Way to go, King!" Meliodas cheered.

"Are you gonna help me or not, Captain?" King groaned, dragging his hands down his face in shame.

"Now, when you say 'everything' do you mean _eeeeeverything_?" Meliodas asked, leering at him. The tone of voice he used and the look on his face frightened King enough for him to hide behind Chastiefol.

"Maybe just a, uh… crash course?" He said quietly.

"Crash course it is!" Meliodas declared, grabbing King by the back of his jacket and slamming him down onto one of the bar stools, yanking up a massive diagram that made King's jaw drop.

" _Where have you been keeping that!?"_

"Unless you want Ban to join us, I suggest you keep it down," Meliodas said, pulling a pointer out of nowhere and slapping the tip at the top of the diagram. "This is the clitoris -"

 _'Oh god what have I done,'_ King thought to himself

XOXOXOXOXOXOXOXOXOXO

"You can do this - think confidence, think confidence -" King muttered to myself as he floated towards Diane in her usual size, was walking peacefully along the outer wall of the city to just admire it.

"Hey, Diane?" The giantess in question turned and looked over her shoulder to see King floating towards her.

"Yeah, King?"

"Are you going to be spending the night in the castle again?" He asked.

"Probably!" She chirped, "It's not that the ground in the Forest isn't soft, but I don't think I've ever slept anywhere as nice as the beds in the castle!"

"What about Chastiefol?" He objected with a small pout, flying in circles around her head, "You love sharing Chastiefol with me!"

"That's true," she hummed, tapping her chin. "But the beds in the castle are different."

"Is it because I'm not there?" He asked; he squawked when Diane grabbed him in her fist and shoved him down the front of her outfit so he was trapped between her boobs. She smirked at the dazed noises of delight coming from King as he made himself comfortable.

"What's all this about, King?" She asked. He mumbled something against her left boob that she couldn't distinguish. "What?"

"I said I missed you last night, okay?" He exclaimed, his entire face red. "I've just…" he drifted off and sank down between her boobs again, barely saying loud enough for her to hear, "I've gotten used to being with you."

"Aw, King!" He yelped again when she grabbed him in her fist once more and began rubbing him against her face happily. "That's so sweet, why didn't you say so?"

"I didn't want to sound too clingy," he admitted shyly, looking away from her face, although he was sitting in her palm with his legs crossed.

"King," Diane said gently, "we've both nearly died multiple times in the past year. I think we both get to be a bit clingy." He looked up and met her eyes, unable to repress an affectionate smile.

"I love you, Diane."

"I love you, too," she said, holding him close to her face; he stood on the heel of her palm and kissed her forehead, smiling at her. "I'll tell you what," she said, "come to the northern side of the castle a little while after sunset, and I'll let you into my room, okay?"

"Northern side?"

"Fourth floor," she winked, moving to stand up. He floated out of her hands to follow her, sitting on her shoulder with a wide smile.

"So you're letting me in through the window? Am I some kind of dirty little secret?" He joked.

"Little? Yes. Secret? Not so much."

"What about the dirty part?" He asked, leaving her shoulder to float in front of her face. She gasped softly and gaped at him in shock; normally he would have apologized profusely and bolted, but he found himself smirking, especially when he saw the pink blooming across her cheeks. "I'll see you tonight, Diane," he said in a low voice, the slightest undertone of teasing in his words. He turned and flew off towards the Boar Hat, leaving Diane to cover her mouth with both hands.

"What just happened?" She whispered to herself.

XOXOXOXOXOXOXOXOXOXO

Diane loved girl time with Elizabeth. The forest was wonderful, but it didn't have her best friend.

"I'm glad that you were comfortable enough here that you accepted my invitation to stay a second night, Diane," Elizabeth said, smiling at her as they sat on the loveseat in Elizabeth's room.

"I was telling King today - the forest is beautiful, and the ground there is pretty soft, but it's got nothing on the beds here in the castle," Diane responded, holding one of the pillows to her chest.

"All the same, it's getting pretty late," Elizabeth said, looking at the starry night sky through the window. "We should get to bed."

"I guess so," Diane hummed, standing up and putting on her shoes. "Same room as last night, right?"

"Are you sure you don't want me to walk you there?" Elizabeth asked.

"No, you get some rest, Elizabeth," she assured her, giving her hand a gentle squeeze before turning to walk down the hall. The door to Elizabeth's room had hardly closed before Diane stopped when a familiar figure appeared ahead of her.

"Howzer?" He wouldn't have even noticed her if she hadn't spoken, but he glanced up when he heard her voice, blinking in surprise.

"Diane," he said, approaching her with a small smile. "I didn't know you were staying in the castle."

"Yeah, Elizabeth invited me," she said, gesturing towards the room belonging to the princess in question. "I'm on my way to the room I stayed in last night."

"One of the guest rooms at the end of the next hall, right?" He said, gesturing over his shoulder. "I'm going that way to get to the grand staircase. How about I escort you?"

"Um, yeah, sure!" She smiled. "So, I've met Celia," she teased once they started walking; Howzer promptly turned beet red and laughed nervously. "I like her so far."

"I'm glad to hear that," he said, a small smile on his face. "I'm sure that she would be, too."

"We actually have a lot in common," Diane said, tapping her chin with her finger.

"Yeah?" Diane hummed and nodded.

"It's funny - see, when the captain first told us about the two of you he said that she had charmed the pants off of you -" Howzer made a strangled noise, but Diane continued, "- and then when King met her he brought that up, and she laughed and said, 'I've been trying!' It was really funny, especially because I said the same thing about King. So, we both like teasing our boyfriends!"

"That's nice," he wheezed.

"Well, this is me!" She said as they came upon the door she had entered the previous night. "It was nice seeing you, Howzer. Are you going to see Celia tonight?"

"Tomorrow morning," he said, his voice strained.

"Well, tell her I said hi!" Diane told him as she entered the room, closing the door as he began to walk away. She listened at the door until the sound of footsteps was gone before turning and approaching the windows, barely giving the lantern that the servants had left for her a cursory glance.

But it was appreciated, since the light of it helped her find the latch on the window and undo it so she could push them open.

"King?" She called out gently, giggling when the fairy appeared above her, floating upside down.

"Did I hear you talking to someone?" He asked her with a playful tone, floating into the room and looking around as Diane closed and locked the window, quickly kicking off her shoes.

"Yeah, I saw Howzer. I was teasing him about Celia," she said, walking over to the vanity and letting down her pigtails.

"Were you, now?" He asked, taking off his jacket and draping it over the back of the loveseat before sitting on Chastiefol and floating back to Diane, taking the brush so he could brush her hair for her; part of their nightly routine.

"Yep. I told him that the two of us have a lot in common."

"I didn't get to see you talk to her much. What is it that you have in common?"

"We both like teasing our boyfriends," she said, closing her eyes and enjoying the feeling of his hands playing with her hair while he brushed it out. His movements stilled; when he didn't respond she turned around to look at him with a small smile, half expecting him to be stunned speechless, the shadows of the lantern making the blush in his cheeks look even darker. But instead, she was surprised to see King looking at her with a small pout.

"You like teasing me?" He said, making her giggle.

"Of course I do," she told him, standing up while cupping his cheek. "You're so cute when you blush." She gasped when his arms slid around her waist and pulled her against him sharply.

"Well, Diane, fair's fair," King said, tilting his head to the side as he smirked, his eyes curving with mischief. "I should get to tease you, too."

* * *

A/N: I know there's some shameless mention of my OC, but it's relevant to the Diane-teasing-King-thing.

Also, I think it's weird that Seven Deadly Sins isn't as popular as some other stuff. Like, RWBY has a shitton more content that Seven Deadly Sins, and it's a web series by _Rooster Teeth_. The episodes are, like, _ten minutes_ long. I'm not salty about that, though, since I love RWBY, too.

I'd just like to have as much Kiane as I can get Jaune/Pyrrha. JUST SAYIN'.


	2. Chapter 2

Separating this into a separate chapter because the other one is just King being awkward and Diane being a tease.

And now we get to the makin' with the love.

* * *

" _Well, Diane, fair's fair," King said, tilting his head to the side as he smirked, his eyes curving with mischief. "I should get to tease you, too."_

Diane gasped and found herself being pushed onto the bed, King pinning her hands on either side of her head with his own, their fingers laced.

"King!" She gasped, staring up at him in shock.

"Diane…" he said her name softly, releasing her hands; she kept them in place, her cheeks turning pink as King's hands trailed playfully down her sides until his palms rested on her hips. Her breathing hitched when his hands moved slowly towards the hem of her dress, his eyes darting back to hers. "Is this okay?" He asked, his cheeks only slightly pink.

"Yes," she said softly, "keep going." She gasped softly when his hands gently caressed her thighs, breathing shakily when his hands slid under the hem of her dress, his thumbs teasingly stroking the fabric of her panties. She moved her hands to grab his face, pulling him down to kiss her when his hands push her dress up to her waist.

"Lace, huh?" He said when he pulled away, smirking at her. "I like it."

"K-King -" she gasped, her eyelashes fluttering when his hands slid up her back towards the button for her dress at the back of her neck.

"Can I take this off?" She could only nod, her heart racing when he chuckled. "Use your words, Diane."

"Y… yes…" she whimpered, gasping as the first button came undone, his hands sliding down her back as he undid the rest. She was clinging to the fabric of his shirt, making it impossible for him to pull her dress off, the fabric collecting at her shoulders

"Diane," he said her name in such a low voice in gave her chills, "let me feel you." She gasped and loosened her grip on his shirt so he could pull the rest of her dress off of her torso. She grabbed onto the pillow again, her legs shaking as she lifted her hips so he could take off her dress completely.

"K-King - the light -" she tried to say, flushing when his eyes dragged up and down her near-naked form on the bed.

"-No," he interrupted her, dragging his hands up her ribs until the settled on her breasts, drawing a genuine moan from her lips. "I want to look at you."

"King -" she whispered his name as he leaned over her and brushed his lips over hers.

"Diane," he sang her name teasingly while smirking at her, taking her hands and guiding them to his belt, "don't you want to take my clothes off, too?" Her hands were shaking at the invitation, fumbling with his belt until it was thrown across the room, quickly followed by his shirt. He made a small noise of alarm when Diane grabbed his shoulders and flipped them over, giggling when his face lit up red. "Wha -?"

"-I'm not gonna let you have all of the fun," she teased, grinding her hips against his while dragging a nail down his chest. She gasped when he sat up quickly, one arm wrapping around her waist while the other pushed between her legs, rubbing the heel of his palm against the heat between her legs.

"That's the point of this, Diane," he purred, "for both of us to have fun." She moaned and grabbed his shoulders, slumping against him when his fingers pressed against a wet spot on her panties. "If this stops being fun at any point, just tell me and I'll stop."

"Don't," she said, shaking her head as her cheeks lit up red, "don't stop."

"Can I keep going?" He asked, smirking as he tilted his head to the side.

"Yes," she breathed, nodding at him, "yes, please - _ah_!" Her head fell forward against his shoulder as his hand slipped down the front of her panties, his middle finger sliding between her lower lips and brushing over something that had her whole body shaking, like bolt of lightning through her that left a pleasurable tingle in its wake. She moaned his name while wrapping her arms around his shoulders, eliciting a moan from him.

She groaned as he rolled them over so he had her on her back, pulling away to look into her eyes.

"Diane," he said her name while breaking their eye-contact long enough to slide her panties down her legs and throw them over his shoulder. He propped himself up on his elbow as he stretched out next to her, his other hand pushing her legs apart. "Spread your legs." Her back arched and she moaned as her legs fell apart, moaning louder when his fingers dipped between her legs again.

She gasped his name again when his finger dipped inside of her, an entirely new feeling she hadn't experienced before. When it slid out of her it passed over that spot that made her whole body jolt, her back arching and her eyes falling closed.

"No," his arm left the space beside her head for his hand to grab her chin, "look at me." She felt so hot she couldn't breathe, panting as she opened her eyes to meet his. "Does that feel good?" He asked, the smirk on his face making her feel even hotter; she could only nod weakly. "Good," he murmured, his finger dipping inside of her again, pulling a cry from her when a second one joined it. She tried to close her eyes again, but she sobbed when he pulled his fingers away.

"King!" She whined.

"Look me in the eyes," he said, circling his fingers around the tiny spot that sent pleasurable jolts through her body, making her toes curl. "If you look away, I'll stop."

"Why?" Diane sobbed.

"Because I want to see it," he said when she met his eyes. "You have the most beautiful eyes in the realm, Diane," he murmured, "and I want to see what they look like when you're filled with ecstasy because of _me_." Her head nearly fell back again when he pushed his fingers inside of her again; she reacted by grabbing his face and pulling him close so their foreheads were pressed together.

"So do it," she challenged him, gasping at the feeling of his fingers curling inside of her, his thumb brushing over the spot that sent the bolts of pleasure through her; it was such a simple move, and yet it triggered a wave of pleasure that washed over her, drawing a cry from her that was silenced by King's mouth over hers. The wave left her quaking, her body falling limp with satisfaction in its wake.

She panted heavily, her skin tingling as King pulled his fingers from her, reaching for the blankets to pull them up and over them. She hummed and curled against him, tucking her head against his neck with a pleased noise when his arms wrapped around her waist.

"So…" he said quietly, raising his hand and snuffing out the flame of the lamp with a flick of his wrist. "That was… good?"

"That was perfect," she said, kissing his neck while rubbing his chest, her fingers trailing towards the waistband of his pants.

"Oh, thank god," he sighed, relaxing completely, "I was worried that I -" he gasped when Diane's hand slipped into his pants, grasping what she felt there.

"I don't exactly have someone like the captain I can go to for advice," she teased, smiling at the embarrassed gurgle he made.

"How did you - _ooohhh_ …" he was cut off by her slow stroking motion, whining as the blankets pooled at her waist when she sat up while moving to yank his pants off.

"I might as well go with what _fits_ ," she purred, throwing her leg over him so she was straddling his thighs, her tongue poking out as she stroked his length.

"D-Diane, I -!"

"Is this okay?" She asked, mirroring the tone he had used earlier.

"Oh god yes," he moaned, choking on air when he felt her slide down his legs, her lips pressing against his hip. "Diane -" he panted her name and his head fell back as he moaned loudly when her tongue swirled around the tip of his length.

"You turned me into a babbling mess -" she said, taking the shaft in her hands, "-the night isn't done until I've returned the favor."

* * *

A/N: Eye-contact while fingering is important, fellow adults. It establishes an _emotional bond_.

And there are some questions that are better avoided. Like: does King even have a penis like a human's? (for the sake of this, yes)

The question that bothers me the most is: What if he ejaculates pollen instead of semen? I mean, he's a fairy and flowers are a big deal for them, and that's how plants reproduce -


End file.
